1. Field of the Invention
This invention relates to power sources, and particularly to an electrical power source giving rise to a voltage through the ionization of gallium by energetic alpha particles.
2. Description of the Related Art
While most people are familiar with electrical power in their homes and office as being available through an electrical socket or junction, all electrical power must be generated in some manner. Industrial-sized processes in plants allow the generation of megawatts of electricity for distribution over an electric grid powering cities and towns as well as major industrial facilities. However, there is a need for electrical power generation in environments that are otherwise isolated from large scale or other electric power grids. Such environments include orbital and deep space as well as open water and deep ocean exploration and activities.
Prior attempts in the art to supply electrical power for circuitry and equipment include the construction of radioisotope thermoelectric generators (RTGs) as well as lithium batteries, rechargeable batteries, and solar cell panels. Each of these forms of power generation has their advantages and disadvantages. They are also well-documented in the art.
In some circumstances, these prior art generators are not generally miniaturized in order to provide low-power sources. Additionally, the efficiencies of these generators leaves room for improvement as they are not significantly close to 100% efficiency. Further, the useful life of these power supplies is generally limited and usually for less than one year without an available energy source by which they may be re-energized or recharged.
Consequently, there is significant room for improvement with respect to low-energy power sources provided on a miniaturized or other basis for space and ocean exploration missions. The present invention provides an alternative to prior art devices as well as advancing the art by delivering more efficient power source that is self contained, long-lasting, and easily incorporated into advanced and highly-optimized equipment.
In view of the foregoing disadvantages inherent in the known types of power sources now present in the prior art, the present invention provides an extremely efficient, very compact, and long-lived power source wherein the same can be utilized for supplying electrical power where it would be unavailable otherwise.
The general purpose of the present invention, which will be described subsequently in greater detail, is to provide an extremely efficient, miniaturized, and long-lived power source which is not anticipated, rendered obvious, suggested, or even implied by any of the prior art power sources, either alone or in any combination thereof.
The present invention uses the kinetic energy of xcex1-particles emitted during radioactive decay. Alpha particles are the nuclei of helium atoms that are emitted by radioactive isotopes. In comparison to beta particles (electrons) and gamma rays (high energy electromagnetic radiation), xcex1-particles have higher LET (Linear Energy Transfer) characteristics which makes them more suited for conversion to electrical energy under the proper circumstances. The present invention provides such circumstances in order to convert the comparatively large quantity of available kinetic energy to electrical energy. With the use of radioactive isotopes, to such a power source can be used in environments where other power sources may not be applicable.
Elemental gallium is a semimetal and is generally a liquid above 35xc2x0 C. (95xc2x0 F.). By placing liquid gallium between a iridium anode and an zirconium cathode, liquid gallium becomes a carrier of current and a target for bombardment by alpha particles emitted by a radioactive isotope, in this case curium-244. When the xcex1-particles collide with the gallium atoms, the gallium atoms become ionized to supply a free electron and a gallium ion with a +1 charge. The free electrons migrate to the iridium anode while the gallium ions migrate to the zirconium cathode. The work function difference between cathode and anode gives rise to a voltage of approximately 1.62 volts which provides a separating electric field for electrons and gallium ions. This provides a corresponding power level of approximately 20 milliwatts per device.
Devices incorporating the present invention can be connected in series to elevate the voltage and in parallel to elevate the current.
The present invention provides a self-contained power source that may be used for powering many different devices not the least of which is electrical circuitry. Such a supply of power can provide power to an otherwise power-isolated environment such as deep space, deep ocean, and other environments. The construction of the device is generally straightforward and the constituent parts are generally available such that manufacture could occur without significant obstacles. In conjunction with curium-244 radioisotope, a useful life of approximately 18 years corresponding to the half-life of curium-244 is expected. With conversion of the approximately 5.8 million electron volts (MeV) of xcex1-particle kinetic energy being converted with a high degree of efficiency to electrical energy.
It is an object of the present invention to provide a power source that is self-contained.
It is another object of the present invention to provide a power source that is long-lived.
It is yet another object of the present invention to provide a power source that is efficient.
It is yet another object of the present invention to provide a power source that is small and/or subject to miniaturization.
It is another object of the present invention to provide a power source that lends itself to use in hostile or isolated environments.
It is yet another object of the present invention to provide a power source that is reliable.
It is another object of the present invention to provide a power source that is readily manufactured.